The disclosure relates generally to distribution of data (e.g., digital data services and radio frequency communications services) in a distributed antenna system (DAS), and more particularly to supporting an add-on remote unit(s) (RU) for new or additional communications services over an existing optical fiber communications medium using radio frequency (RF) multiplexing.
Wireless customers are increasingly demanding digital data services, such as streaming video signals. Concurrently, some wireless customers use their wireless devices in areas that are poorly served by conventional cellular networks, such as inside certain buildings or areas where there is little cellular coverage. One response to the intersection of these two concerns has been the use of DASs. DASs can be particularly useful when deployed inside buildings or other indoor environments where client devices may not otherwise be able to effectively receive RF signals from a source. DASs include RUs (also referred to as “remote antenna units (RAUs)”) configured to receive and wirelessly transmit wireless communications signals to client devices in antenna range of the RUs. Such DASs may use wireless fidelity (WiFi) or wireless local area networks (WLANs), as examples, to provide digital data services.
A typical DAS comprises head end equipment (HEE) communicatively coupled to a plurality of RUs. The HEE connects to a variety of wireless services, such as wideband code division multiple access (WCDMA), long term evolution (LTE), and WLAN communications services. A plurality of RUs is deployed inside buildings or other indoor environments to form RF antenna coverage areas. Each of the RUs contain, or is configured to couple to, one or more antennas configured to support desired frequency(ies) or polarization to redistribute the variety of wireless services to client devices in the respective RF antenna coverage area. The DAS may employ optical fiber as an optical fiber-based DAS to support reliable downlink distribution of the variety of wireless communications services from the HEE to the RUs and vice versa for uplink distribution. Each RU is communicatively coupled to the HEE through an optical fiber pair—one downlink optical fiber provided for downlink communications and one uplink optical fiber provided for uplink communications. Optical fiber enjoys the benefit of large bandwidth capability with low noise over a conductor-based communications medium. However, fast advancement of wireless technologies and growing user demand for new or additional wireless communications services may exceed the capabilities of the existing, installed RUs in the optical fiber-based DAS even if the installed optical fiber communications medium has additional bandwidth availability to support such new or additional wireless communications services. As a result, new RUs may need to be added to the installed optical-fiber based DAS, but additional optical fiber must be installed to provide optical communications between the new RUs and the HEE.
No admission is made that any reference cited herein constitutes prior art. Applicant expressly reserves the right to challenge the accuracy and pertinency of any cited documents.